<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8" />
    <meta http-equiv="X-UA-Compatible" content="IE=edge" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <link rel="stylesheet" href="./css/inputnumber.css" />
    <link rel="stylesheet" href="./css/index.css" />
    <title>购物车</title>
</head>

<body>
    <div class="app-container" id="app">
        <!-- 顶部banner -->
        <div class="banner-box"><img src="./img/fruit.jpg " alt="" /></div>
        <!-- 面包屑 -->
        <div class="breadcrumb">
            <span>🏠</span>
            /
            <span>购物车</span>
        </div>
        <!-- 购物车主体 -->
        <div class="main" v-if="fruitList.length >  0">
            <div class="table">
                <!-- 头部 -->
                <div class="thead">
                    <div class="tr">
                        <div class="th">选中</div>
                        <div class="th th-pic">图片</div>
                        <div class="th">单价</div>
                        <div class="th num-th">个数</div>
                        <div class="th">小计</div>
                        <div class="th">操作</div>
                    </div>
                </div>
                <!-- 身体 -->
                <div class="tbody">
                    <div class="tr " v-for="(item,index) in fruitList" :key="item.id" class="tr"
                        :class="{active:item.isChecked}">
                        <div class="td"><input type="checkbox" v-model="item.isChecked" /></div>
                        <div class="td"><img :src="item.icon" alt="" /></div>
                        <div class="td">{{item.price}}</div>
                        <div class="td">
                            <div class="my-input-number">
                                <button :disabled="item.num <= 1" class="decrease" @click="sub(item.id)"> - </button>
                                <span class="my-input__inner">{{item.num}}</span>
                                <button class="increase" @click="add(item.id)"> + </button>
                            </div>
                        </div>
                        <div class="td">{{item.num * item.price}}</div>
                        <div class="td"><button @click="del(item.id)">删除</button></div>
                    </div>
                </div>
                <!-- 底部 -->
                <div class="bottom">
                    <!-- 全选 -->
                    <label class="check-all">
                        <input type="checkbox" v-model="isAll"/>
                        全选
                    </label>
                    <div class="right-box">
                        <!-- 所有商品总价 -->
                        <span class="price-box">总价&nbsp;&nbsp;:&nbsp;&nbsp;¥&nbsp;<span class="price">{{totalPrice}}</span></span>
                        <!-- 结算按钮 -->
                        <button class="pay">结算( {{totalCount}} )</button>
                    </div>
                </div>
            </div>
        </div>
        <!-- 空车 -->
        <div class="empty" v-else>🛒空空如也</div>
    </div>
    <script src="https://cdn.jsdelivr.net/npm/vue@2.7.16/dist/vue.js"></script>
    <script>
        const defaultArr = [{
                        id: 1,
                        icon: './img/火龙果.png ',
                        // http://autumnfish.cn/static/火龙果.png
                        isChecked: true,
                        num: 2,
                        price: 6,
                    },
                    {
                        id: 2,
                        icon: './img/荔枝.png',
                        isChecked: false,
                        num: 7,
                        price: 20,
                    },
                    {
                        id: 3,
                        icon: './img/榴莲.png',
                        isChecked: false,
                        num: 3,
                        price: 40,
                    },
                    {
                        id: 4,
                        icon: './img/鸭梨.png',
                        isChecked: true,
                        num: 10,
                        price: 3,
                    },
                    {
                        id: 5,
                        icon: './img/樱桃.png',
                        isChecked: false,
                        num: 20,
                        price: 34,
                    }]
        const app = new Vue({
            el: '#app',
            data: {
                // 水果列表
                fruitList: JSON.parse(localStorage.getItem('list')) || defaultArr
            },
            computed:{
                //默认计算属性只能获取不能设置，要设置需要写完整的写法
                // isAll(){
                //     //必须所有的小选择框都选中，全选按钮才会选中 -> every
                //     return this.fruitList.every(item => item.isChecked === true)
                // }
                isAll:{
                    get(){
                        return this.fruitList.every(item => item.isChecked === true)
                    },
                    set(value){
                        //基于拿到的布尔值，要让所有的小选择框 同步状态
                        this.fruitList.forEach(item => item.isChecked = value);
                    }
                },
                //统计我们选中的总数
                totalCount(){
                    return this.fruitList.reduce((sum,item)=>{
                        if(item.isChecked){
                            //选中了才需要累加
                            return sum = sum + item.num
                        }else{
                            return sum
                        }
                    },0)
                },
                //统计我们选中的总价格
                totalPrice(){
                    return this.fruitList.reduce((sum,item)=>{
                        if(item.isChecked){
                            //选中了才需要累加
                            return sum = sum + (item.price * item.num)
                        }else{
                            return sum
                        }
                    },0)
                }
            },
            methods: {
                del(id) {
                    this.fruitList = this.fruitList.filter(item => item.id !== id)
                },
                add(id) {
                    //根据id找到数组中的对应项 ➞ find
                    const fruit = this.fruitList.find(item => item.id === id)
                    fruit.num++
                },
                sub(id) {
                    const fruit = this.fruitList.find(item => item.id === id)
                    fruit.num--
                }
            },
            watch:{
                fruitList:{
                    deep:true,
                    handler(newValue){
                        //需要将变化后的newValue存入本地(转JSON),即存入浏览器中
                        localStorage.setItem('list',JSON.stringify(newValue))
                    }
                }
            }
        })
    </script>
</body>

</html>